Art oe placer-mining



J. C. PATTERSON.

ART OF PLACER MINING. v

' APPLICATION FILED FEB- 251 19H. v 1,325,263, v Patented Dec. 16,1919.

3 SHEETS-SHEET I.

John Curtis Paifarsom lwwmon- J. C. PATTERSON.

ART OF PLACER MINING.

APPLICATION FILED FE8.26. 1911.

Patented Dec. 16, 1919.

3 SHEETS-SHEET 2.

Jbim Ourfis Paiiaraon;

1. C. PATTERSON.

ART OF PLACER MINING.

APPLICATION FILED FEB. 26. 1911.

1,325,263. Patented De.16,1919.

3 SHEETS-SHEET 3- FIG'LZIT UNITED STATES PATENT OFFICE.

JOHN CURTIS PATTERSON, 0F EHILADELPHIA, PENNSYLVANIA.

ART or PLACER-MINING,

. To all whom it may concern:

Be it known that I, JOHN CURTIS PATTER- SON, of Philadelphia, in thecounty of Philadelphia and State of Pennsylvania, have invented certainnew and useful Improvements in the Art of Placer-Mining, whereof thefollowing is a specification, reference being had to the accompanyingdrawings.

In order that the nature of my invention may be more readily understood,I have thought it best to preface the description with a generalstatement in regard to the method usually employed heretofore for thesame general purpose, taking as a typical instance both ofthe old artand of the employment of my invention, a case where the work is to beconducted upon the bed of a stream of running water, the illustrationsshown in the drawings being mainly diagrammatical.

In Figure I, I have illustrated, conventionally, in transverse section,a bed of .a stream in connection with devices employed in the methodheretofore practised.

Fig. II, is a plan view illustrative of said old devices and method, ona reduced scale.

Fig. III, is a planview of a stream illustrative of the devices andmethod employed in practising my invention.

Fig. IV, is a transverse section of'the stream illustrative of mymethod, the scale of this figure being enlarged and substantiallysimilar to that of the scale of Fig. I.

Referring now to Figs. I, and II, 1, represents the rocky underlyingsurface of a stream bed, 2-, the gravel orother relatively non-coherentmaterial constituting the removable bed of the stream, and carrying themetallic values which are to be separated from the gangue. The dottedlines at 8, indicate the normal water level of thestream.

Heretofore the method of conducting placer mining upon streams of thischarac ter wasby the use of structures known as wing dams, of which atypical instance is illustrated in Figs. I, and II. A longitudinal dikeof crib work, indicated comprehensively at 4, and built up ordinarily oftimbers 5, and 6, placed in alternate pairs and ballasted by pieces ofrock 7 was so constructed along the center of the stream bed,followingsubstantially the general course of the stream so as to dividethe area as nearly as possible into two equal channels, the direction offlow being indicated by the arrows in Fig. II. At the up Specificationof Letters Patent.

stream extremity, this central dike of crib 1 Patented Dec. 16, 1919.Application filed February 26, 1917. Serial No. 150,894.

part of the wing dam. In this manner the water was diverted from thatportion of the channel which lay between the longitudinal dike and theadjacent bank at the side to which the wing dam 10, extended, the lengthof the denuded portion of the bed being of course determined by thelongitudinal extent of the dike 4. As a result of this method of.procedure, the water of the stream, whose normal level is indicated in-Fig. I, by the dotted line 3, was crowded into the remaining channelshown at the left hand side of Fig. I, or the side nearest the observerin Fig. II, and by reason of the diminution of area of cross-section,rose to a level which may be taken as that indicated .at 11. The gravel,etc., of the stream bed at the dammed ofi side of the dike t, was thenremoved in any of the ways characteristic of placer mining, and afterthis the wing dam, represented at 10,'was torn down, or disconnectedfrom its original location, and was rebuilt or reconnected to theopposite bank of the stream, so as to repeat upon the other side of the.dike 4, the procedure above described. As thus conductecl, themethodwas open to serious disadvantages among which may be noted thefollowing:

Owing to the structure of the crib work employed, not only was arelatively large portion of the value-bearing bed directly covered bythe dike itself, but, in order to insure stability of the dike, theexcavation of the uncovered portions of the bed was greatly restricted.Thus, in Fig. II, I have indicated by the dotted lines 15, and 16,respectively, the angle of slope oneach side of the dike 4, which wascharacteristic of the necessary amount of residual material, saidmaterial being thus practically lost for the purposes of the miningoperation. Speakstream.

cally only one such dike could be employed in any given portion of thestream, and consequently the water pressure due to the increased levelwas relatively high. I

By the method which I have invented,

these objections may be substantially ohviated and other advantagesmaybe derived, under similar condltlonsr 7 Referring now to Figs. III,and IV, 21,

represents the rocky bottom of the creek, 22,

other members adapted to serve as rails, are lttlCllongitudinally,withthe stream to form a track. corresponding in length to the desired.length of thedam. Upon the tracks thus formed, a car or platform 30,provided with rollers31, is supported, said car carryingapile drivers,comprehensively indicated at1.34, and 35, respectively Since the detailsof such mechanism is well understood, it is not deemed necessary to givemore than a conventional representation thereof.

The stream is then divided longitudinally into a plurality of channels,preferably three in number, as illustrated in Figs. III, and IV, bymeans of sheet-piling, formed of steel, extending down through the valuebearing loose material, the sheets having interlocking edges which maybe made substantially water-tight and being of such rigidity that theirlower extremities can be driven firmly into the rocky bed 21, of the Asthese sheets are successively seatedv in place they may be stayed at theupper extremities by cross-braces 36, and 37 abutting. against theuprights 24, and 25. This adjunctive device, however, may not benecessary inv all cases. At the upstream extremity the central channelthus formed between the walls of sheet piling 38, and 39, is closedby asmall crib work 40, (see Fig. III) having adouble inclined upper end, orby any other suitable deviceadapted to exclude water-from the centralchannel and divert it to the side channels.

Under these circumstances, the conditions illustrated in Figs. III, andIV, .will exist, the water level being raisedin the respec tive sidechannels to a degree illustrated at 41, and 42, .so that the externalpressure against .thenlongitudinal walls is relatively much lessthan-that whichwas characteristic of the method-shown in Figs. 1, andII;

The value-bearing material in-the central channel is then excavated, theremoval being complete. After this the crib or head of the wing dam 40,is removed. The water is then allowed to reenter the central channel,said wing dam being reconstructed at the up-stream end of one ortheother of the side channels previously formed.

Under these circumstances, the water will be diverted from that sidechannel and the excavation of thebed thereof can proceed to the utmostextent required. Then this is completed the wing dam crib is removed tothe upstream end of the remaining. channel and the water is divertedtherefrom so that the bed of said channel can-be excavated.

The braces shown at 36, and 37, may be so constructed and attached as toconstitute either compression members or extension members forthesupport of the sheet-piling, but obviously if the pressure due tothedivergence of the water from either of. the side channels be so high asto endangerthe structure, props or other adjuncts may be employed tosupport the wall.

It will thus be seenthat by theemployment of my invention, the amount ofvaluebearing material which is directly covered by any portion of thestructure is reduced .to a minimum, since even though a crib be employedfor the transverse wing: dam memher, the cross-sectional area thereof isrela tively very small. It is obvious however, that even this coveredarea may be reduced by the employment of sheet-piling or :other devicesto constitute the angularupstream extremity of the wing dam.

I am aware that the use of sheet piling with interlocking edges, is notnew, and the reference thereto in the foregoing; specification is simplyto indicate a preferred feature employed in carrying out the procedurecharacteristic of my invention.

Having thus described my invention, I claim:

1. The hereinbefore described improvement in the art of placer mining ofa stream, which consists inseparating the water area of the stream andthe value-bearing loose material, for an extended distance, intov aplurality of longitudinal ichannels, thinly divided from one another bymeans extending down through said loose material; successively closingthe upstream extremities of the channels so formed while permitting thewater to flow through anopen channel; and successively removing thevalue-bearing material from each closed channel.

2. The hereinbefore described improvement inthe art of placer mining ofa stream, which consists in separating the water area of the stream andthe value-bearing loose material, for an extended. distance, .into threeormore longitudinal channels, thinly divided from one-another by meansextending through said loose material; proceeding, in permutation, toclose the up-stream extremity of a channel, While permitting the Waterto fioW through the others; and successively removing the value-bearingmaterial from each closed channel.

In testimony whereof I have hereunto signed my name at Philadelphia,Pennsylvania, this twenty-first day of February, 191

JOHN CURTIS PATTERSON. Witnesses:

JAMES H. BELL, E. L. FULLERTON.

